The man at the piano is the famous bluesman Pinetop Perkins. He will die, at age 97, within a year of this unusual outdoor performance.

He plays beautifully, although his old hands can’t manage the “bass rolling like thunder,” as he puts it, like they used to. He ends every tune with either a couple of bars of “Jingle Bells” or another ubiquitous ditty I can’t name. At which point he drags on the cigarette that rests on the left side of the keyboard, or lights a new one.

He also complains about the piano’s tuning. Repeatedly. He appears to have forgotten that he’s already made the complaint (he’s 96, after all), so he just keeps on making it. And in a way, the repetition (“It’s out of tune on the B”) becomes its own form of blues.

Kjartansson is an effervescent Icelander interested in music, melancholy, and duration. Also, with American culture, which he once described as “so banal in so many ways. There’s always something wrong in America, and that sort of enchants me a bit.”

Perkins is really singing his tune, you feel, when he launches into: “Got my mojo working./Got my mojo working./Got my mojo working./Got my mojo working, but it just won’t work on you.”

I don’t know how great “The Man” is. It’s not up there — either as an idea or an experience — with Kjartansson’s “The Visitors,” the multi-screen video installation which showed at the ICA two years ago and has achieved cult status. (Both works were given to the ICA by Graham and Ann Gund.)

When “First Light” opened in October, the same gallery was showing Sharon Hayes’s “Ricerche: three.” An artfully filmed, outdoor interview about sex and politics with female college students, the film was inspired by “Love Meetings,” a 1965 documentary by Pier Paolo Pasolini. Sophisticated, sly, and unaccountably touching, it is a superior work of art to Kjartansson’s “The Man.” When I returned to the ICA earlier this week, I was sorry it was no longer on view.

But on this particular day, Kjartannson’s piece was just my speed. I found myself falling into its gorgeous, almost unchanging wide-screen palette (Perkins and his piano in silhouette against a field of tawny grass and a pale blue sky gradually gilded by the descending sun) and into the music, and I was happy for it to continue.

Going to art museums is like this, isn’t it? You can’t know in advance what is going to cast its spell, or indeed if anything will on that particular day. You might not have envisaged that on a wintry, workaday Tuesday morning you would choose to sit for 49 minutes staring at a field and listening to Delta blues. But you do. And you find that nothing else quite answers to your spiritual state on this day.

You leave charmed, amused, a little nonplussed, both wanting and not wanting to make sense of the experience. Your heart feels like it’s hanging on a slightly different peg.

But actually, nothing much about anything has changed. The sun is slightly lower, true. But it will rise again tomorrow.

On the way in, or out, you note the wall label. Its unspoken assumption is that things — many things, big things — should
change. Kjartansson’s film, it notes disapprovingly, “participates in a century-long history of white people’s celebration, and exploitation, of the innovation and perceived authenticity of black musicians.”

You register this. Quite so. Indisputable. Kara Walker’s
wall piece — also showing black people in silhouette — is there in a nearby gallery to deepen the idea.

But then, as you marvel at the chops of this 96-year-old bluesman — his left hand playing the bass line with syncopated jabs, his right improvising gorgeously fluid runs (Perkins became the oldest person ever to win a Grammy the month before he died) — you get to thinking about other things.

About repetition, failure, and falling short, perhaps. Or the different ways we have of running down the clock. Or of reckoning with the poor cards we’ve been dealt. And maybe also (because it’s the blues, after all) you get to thinking about love:

Used to have so many customers,

Took me a whole week to get around

But don’t you worry darling

Swear I ain’t gonna let you down.

The shadows have lengthened. The birdsong has grown louder. Another truck goes past on the highway. Exit, stage left.